WO2004026277A1

WO2004026277A1 - Method for the extemporaneous preparation of cosmetic compositions having the texture of a cream and compositions for carrying out said method

Info

Publication number: WO2004026277A1
Application number: PCT/FR2003/002732
Authority: WO
Inventors: Martine Seu-Salerno; Laurence Fillardet; Virginie Boulier
Original assignee: Lcw - Les Colorants Wackherr
Priority date: 2002-09-17
Filing date: 2003-09-16
Publication date: 2004-04-01
Also published as: JP2006509732A; JP2017149738A; JP2015052010A; US20060182772A1; JP6162919B2; JP2010111681A; FR2844448B1; US8226961B2; AU2003279426A1; JP4559225B2; US20130164354A1; US8715703B2; FR2844448A1

Abstract

The invention relates to a method for the preparation of cosmetic compositions having the texture of a cream. Said preparation is made at the time when the composition is used and includes bringing the following elements into contact with each other: (A) a liquid phase; (B) a powder containing a gelling agent for the liquid phase (A); and (C) an active cosmetic ingredient, whereby the elements are brought into contact by adding phase (A) to phase (B), subjecting a solid powder containing phase (B) and phase (A) in an immobilized form to mechanical stress, said mechanical stress releasing phase (A). The invention also relates to compositions which can be used in the above context, especially (1) compositions containing phase (B) (to which phase (A) is added prior to use); and (2) solid compositions comprising phase (B) and phase (A) in an immobilized form (and which are transformed into a cream when they are applied to the skin).

Description

Method for the extemporaneous preparation of cosmetic compositions having the texture of a cream, and compositions for the implementation of this method.

The present invention relates to methods for preparing cosmetic compositions having the texture of creams, intended in particular for application to the skin. More specifically, the present invention relates to compositions which can be stored and transported in the form of a powder, and which can be transformed into a composition having the texture of a cream at the time of their application. Thus, the present invention relates in particular to compositions in the form of powder, which are transformed into compositions of creamy texture by addition of a liquid, aqueous or oily phase, this liquid phase being able to be added to the powder by a user (consumer for example) just before its implementation, or else this liquid phase being present from the start within the solid composition, in immobilized or encapsulated form, this encapsulated liquid phase then being released under the effect of mechanical stress , in particular by applying the composition to the surface of the skin.

At the present time, numerous cosmetic compositions are known which have the texture (consistency) of a cream. By their structure and pleasant feel, and by their ability to convey active ingredients, these compositions are widely used in the field of cosmetics.

However, compositions having the consistency of a cream can generally be obtained only by industrial processes. However, at the present time, we see an increasingly marked trend developing for so-called "nomadic cosmetics" compositions which are obtained by mixing powders or liquids included in single doses (capsules, small jars, small sachets. ..), the mixing of the various constituents being carried out by the user just before use. These nomadic cosmetic compositions often have the advantage of not containing preservatives, which makes them particularly suitable for sensitive skin. The object of the present invention is to provide solid compositions for producing nomadic cosmetic compositions allowing the preparation by a user of compositions having the consistency of a cream (that is to say having the organoleptic qualities of a cosmetic cream, and including a soft and pleasant touch, and a milky appearance), without having to do industrial processes to do this.

In this context, the inventors have surprisingly discovered that the simple addition of a liquid phase in a solid powder comprising a gelling agent of a liquid phase (A) and mineral or organic particles (such as, for example, particles of mineral oxides, surface-modified or not, or else particles of polymers) having surface properties giving them a low affinity with respect to said liquid phase, generally leads to an extremely rapid (even instantaneous in in most cases) obtaining a composition having the texture of a cream, without having to use industrial mixing conditions. Particularly unexpectedly, the inventors have moreover demonstrated that, if the mixing of the liquid phase and the powder is carried out under certain particular operating conditions, it leads to the production of a composition integrating the liquid phase, but remaining in the solid powder state, and the solid powder obtained is transformed, under the effect of a mechanical stress which releases the immobilized phase (A) (in particular by application of the powder to the surface of the skin), into a composition with a creamy texture.

On the basis of these discoveries, the aim of the present invention is, in general, to provide a method allowing the preparation of cosmetic compositions having the texture of a cream in an extemporaneous manner, that is to say at the time of the application of these compositions.

Specifically, the invention sets particular objective in this context to provide a method of instantaneous or at least very rapid preparation of such compositions, suitable for use by a consumer, to prepare the composition just before its application. The invention also aims to provide solid compositions leading, by adding a liquid phase (preferably water), to a cosmetic composition of a creamy nature.

Another specific object of the invention is to provide particular cosmetic compositions, transportable and storable in the form of solid powder and which transform into a composition with a creamy texture when they are applied to the skin.

Thus, according to a first aspect, the subject of the present invention is a process for preparing a cosmetic composition having the texture (consistency) of a cream, implemented by a user at the time of application of said cosmetic composition, this process typically comprising a step (E) consisting in bringing into contact:

(A) a liquid phase;

(B) a solid powder comprising: (i) a gelling agent for the liquid phase (A);

(ii) nature of the ^particles, inorganic or organic having surface properties giving them a low affinity vis-à-vis the liquid phase (A); and

(C) a cosmetic active principle, which is generally present within the liquid phase (A) or within the powder (B) or else which constitutes, in whole or in part, the liquid phase (A) or powder (B).

By "liquid phase" is meant, within the meaning of the present description, a phase of aqueous nature or of oily nature. Alternatively, the liquid phase (A) used in the process of the present invention can be a water-in-oil type emulsion (it will then be considered as an "oily nature" phase within the meaning of the present description ) or else of the oil-in-skin type (if necessary, this phase will be considered here as a phase "of an aqueous nature"). As a general rule, the gelling agent (i) can be chosen from any agent capable of gelling the liquid phase (A), that is to say an agent capable of ensuring an increase in viscosity of said phase and its transformation into the form of a gel, generally by obtaining a viscosity of at least 800 mPa.s, and preferably of at least 1000 mPa.s (advantageously of at least 2000 mPa.s). Most often, it is preferred that the gelling agent (i) is chosen from the gelling agents ensuring the fastest possible gelling of the liquid phase (A) during the mixing of said agent and said phase, this gelling being preferably instantaneous . Thus, in general, the gelling agent (i) used in the process of the present invention induces the increase in the viscosity of the liquid phase (A) by gelling less than 5 minutes after mixing, and advantageously less than 1 minute after mixing. Even more preferably, the gelation takes place less than 20 seconds after mixing and, in a particularly preferred manner, less than 10 seconds (or even less than 5 seconds, or advantageously even less) after mixing. It is also preferable, in general, for the gelling agent (i) to be able to integrate a large quantity of phase (A).

The particles (ii) of mineral oxide present in the solid powder (B) are, typically, particles which have surface properties capable of giving them a low affinity with respect to the liquid phase ( AT). In other words, the particles (ii) have a surface of hydrophobic nature if the phase (A) is of aqueous nature, and a surface of hydrophilic nature if the phase (A) is of oily nature. So, . when the liquid phase (A) is an aqueous phase or an emulsion or the continuous phase is aqueous, the particles (ii) are generally particles of hydrophobic polymers, mineral particles (metal oxides for example) grafted by groups of nature hydrophobic, or particles on the surface of which compounds of a hydrophobic nature (such as oils) are deposited. When phase (A) is an oily phase, or an emulsion where the continuous phase is oily, the particles (ii) are advantageously particles of lipophobic nature (for example mineral particles, such as oxides optionally grafted by groups of lipophobic nature, or else inorganic or organic particles on the surface of which water or an aqueous phase is deposited).

In general, whatever their exact nature, the particles (ii) preferably have an average size less than or equal to 5 microns, and preferably less than or equal to 3 microns, this size being typically of the order of a few tens from nanometer to a few hundred nanometers.

By “cosmetic active principle” is meant here, in the broad sense, any compound or mixture of compounds, capable of giving the composition obtained according to the process of the invention a cosmetic character, by conferring for example on this composition an effect of optical nature (dye, brightener, sun filter, etc.); or a cosmetic treatment effect (perfume, antiperspirant, hydrating agent, slimming agent, etc.). Typically, a cosmetic agent (C) according to the invention can in particular be a coloring agent (solid pigment or soluble dye, for example).

Whatever its nature, the cosmetic active principle (C) used in the process of the present invention can vary to a large extent, depending in particular on the nature of the liquid phase (A) and the solid powder (B ) implemented. Most often, this cosmetic active principle is either integrated into the solid powder (B) (in particular if it is a solid or a liquid insoluble in phase (A)), or integrated into the phase liquid (A) (for example if it is an active ingredient soluble in this phase). The cosmetic active principle (C) may constitute all or part of the liquid phase (A) or else of the solid powder (B). According to a particular variant, the liquid phase (A) and the liquid phase (B) can both comprise cosmetic active agents, identical or different.

The process which is the subject of the present invention is in fact a method allowing the preparation of a cosmetic composition, by a user at the time of the use of said cosmetic composition. According to a first possible variant, the method of the invention can consist of a simple addition of phase (A) to the solid powder (B), or, more generally, to a mixture of the two phases (A) and ( B). In this case, the method of the invention can in particular be implemented by a user in the context of the preparation of a "nomadic" cosmetic composition. In this case, just before use, the user adds phase (A) to the powder (B) (for example water or even an aqueous composition, or an oil containing or not containing active principles) to ultimately obtaining a cosmetic composition having the consistency of a cream. In this case, the composition is generally formed instantaneously or almost instantaneously during mixing, that is, most often in less than 30 seconds, and advantageously in less than 5 seconds, under reserve to carry out a minimum homogenization of the mixture. This process can thus be used in particular for the instant "nomadic" preparation of a cosmetic composition. In this context, the mixing of phase (A) and solid (B) can typically be carried out by adding phase (A) to phase (B) contained in a capsule-type container, gelation then being generally obtained. simply by inverting the capsule containing the mixture two or three times, thereby obtaining the desired creamy texture composition. The mixture of phase (A) and phase (B) can also, more simply, be carried out in the palm of the user's hand.

According to another possible variant for the process of the invention, phase (A) can be immobilized on a solid support (adsorbed or deposited on this support) or encapsulated within a solid support, this solid support constituting in all or part of the powder (B). Thus, according to this variant, the solid support can for example be dispersed within the powder (B), or else the powder (B) as a whole serves as a support for phase (A). In this particular variant, step (E) of the process of the invention consists in releasing the phase (A) immobilized within the solid support, by subjecting the powder (B) integrating the phase (A) in immobilized form to a mechanical stress, (this mechanical stress can in particular be carried out by application of the powder (B) integrating phase (A) on the surface of the skin). According to this second variant, the powder (B) integrating phase (A) can be considered as a precursor in solid form of the composition in the form of cream which will be obtained in fine.

Whatever variant is used, the process of the invention must, in general, be adapted according to the nature of the liquid phase (A) which is used.

Thus, according to a first aspect, phase (A) implemented in the process of the invention can be a phase of an aqueous nature. If necessary, it is generally water, an aqueous solution, or even an oil-in-water type emulsion. This aqueous phase may or may not contain active ingredients.

When phase (A) is an aqueous phase, the gelling agent (i) can in particular be chosen from gelling agents of aqueous phases of natural origin usually used in cosmetics, and in particular from gelling agents of plant origin , such as extracts from seeds, plants, fruits or algae, or alternatively among gelling agents of microbial origin such as exocellular derivatives, or alternatively among gelling agents of animal origin such as proteins (in particular milk), gelatins or chitosans. They may also be gelling agents of mineral origin, in particular clays or amorphous silicon dioxides. They can also be compounds of semi-synthetic origin such as modified celluloses or modified starches, or of synthetic origin such as acrylic compounds or polyacrylamides. Particularly preferably, the gelling agent (i) is a starch, generally crosslinked, and preferably modified by carboxymethyl groups, or else it is modified cellulose, agar-agar, or an alginate. .

Furthermore, more generally, when phase (A) is of an aqueous nature, it is preferred that the gelling agent (i) is such that, when it is emulsified in water at a rate of 2% in mass, one obtains, in a duration at most equal to 5 minutes (advantageously in less than 1 minute, and even more advantageously in less than 10 seconds, and preferably instantaneously, that is to say in less than 5 seconds, or even less), a gel having a viscosity at least equal to 800 mPa.s, preferably equal to 1000 mPa.s, and advantageously greater than or equal to 2000 mPa.s .

A gelling agent (i) which is particularly advantageous in the process of the invention when phase (A) is a phase of an aqueous nature, is a crosslinked starch, modified by carboxymethyl groups, and having a molecular mass of between 100 and 10 ^δ g / mol (advantageously between 500,000 and 100,000,000 g / mol), this molecular mass preferably being between 5,000,000 and 50,000,000 g / mol, and advantageously between 25,000,000 and 35,000,000 g / mol. A gelling agent (i) which is particularly advantageous according to the process of the present invention is starch modified with carboxymethyl groups of mass equal to 30,000,000 g / mol which is marketed by the company LCW under the name of "Covagel" (carboxymethylated starch sodium).

More generally, when phase (A) is an aqueous phase, it is possible to use, as gelling agent (i) any crosslinked and substituted starch (preferably weakly substituted, with carboxymethyl groups. When l gelling agent (i) is a starch, it is preferred that it be such that, by mixing this starch with water in a content equal to 2% by mass, one obtains in a duration at most equal to 10 minutes (advantageously in less than 5 minutes, or even in less than 30 seconds), a gel with a viscosity of between 3000 and 6000 mPa.s.

When phase (A) is an aqueous phase, the particles (ii) are generally either particles on the surface of which an oily phase is deposited (for example particles impregnated with an oil), or particles of hydrophobic polymers , or inorganic particles (for example metal oxides), grafted (treated) at the surface by groups of hydrophobic nature, preferably chosen from silane groups or alternatively from methicone, dimethicone, fatty acids, amino acids, lecithin groups , polyethylene, teflon, lauroyl lysine, fluorinated groups (and in particular ethers of polyfluorophosphate, and preferably perfluoroalkylphosphates), as well as mixtures of one or more of such groups, in particular mixtures of polyacrylate / silicone, polyacrylate / lecithin, polyacrylate / fluorinated groups, polyacrylate / silicone / fluorinated groups, or still more silicone / fluorinated groups, the silane groups and the fluorinated groups such as the ethers of polyfluorophosphates being particularly preferred groups.

In the case where the particles (ii) are mineral particles grafted on the surface by groups of hydrophobic nature, it is preferred that these particles are based on metal oxides, and generally based on silica, titanium oxide, alumina, iron oxide or a mixture of these oxides. Particularly advantageously, the particles (ii) are particles based on titanium oxide, comprising, where appropriate, most often less than 90% by mass of titanium oxide and preferably at least 95% by mass. These particles based on titanium oxide have an average size generally less than or equal to 5 microns, preferably less than or equal to 1 micron, and more advantageously between 20 and 100 nm.

In a particularly advantageous manner, when phase (A) is an aqueous phase, the particles (ii) may be particles of oxide, in particular of titanium oxide, grafted with silane groups, these particles then being, in a particularly preferred manner, particles of titanium oxide treated with a silane of formula RSi (OR ') ₃ , where R denotes an alkyl group having from 5 to 18 carbon atoms, R preferably representing a hexyl, heptyl radical, octyl, nonyl, decyl, or undecyl, and where R 'represents an alkyl group comprising from 1 to 5 carbon atoms, R' preferably representing a methyl, ethyl or propyl group. As titanium oxide particles grafted with silane groups which can advantageously be used in this context, mention may be made of particles resulting from treatment with a trimethoxycaprylylsilane or with a triethoxycaprylylsilane. When phase (A) is an aqueous phase, this phase (A) can be encapsulated in a solid support or else immobilized, that is to say adsorbed or supported on the surface of a support solid, this solid support being dispersed within the powder (B) or constituting the powder (B). In this case, step (E) consists in releasing phase (A) by subjecting the powder (B) integrating this phase (A) in encapsulated or immobilized form, to mechanical stress, the application of this mechanical stress being able to in particular be carried out by applying the powder (B) integrating phase (A) to the surface of the skin. In this case, the powder (B) which integrates phase (A) is a precursor of the cosmetic composition having the texture of a cream which will be obtained following application. Preferably, when phase (A) is an aqueous phase, this phase (A) can be immobilized on the surface of particles grafted with silanes, these particles then advantageously being particles of titanium oxide grafted with silane groups as defined above.

According to another variant of the invention, phase (A) used can be an oily phase, and it can thus in particular be an oil of plant or animal origin or a synthetic oil , or alternatively an emulsion of the water-in-oil type, this phase of oily nature comprising, or not, an active cosmetic compound.

In the case where phase (A) is oily in nature, the gelling agent (i) can be chosen, in general, from micas (and in particular modified micas), silicas (preferably lipophilic), and clays, modified or not. Micas, and in particular modified micas, as well as hydrophobic silicas are particularly preferred. In a particularly advantageous manner, the gelling agent (i) is a modified mica, in the case where phase (A) is of oily nature. By way of example, particularly interesting micas are fluorinated micas, and in particular fluorinated micas modified with potassium, such as, in particular, aluminum silicate, fluoromagnesium and potassium (aluminum fluoro magnesium potassium) sold by the LCW company under the name of "Submica M". When phase (A) is an oily phase, the particles (ii) can advantageously be mineral particles, and in particular oxide particles, preferably constituted wholly or partly by a titanium oxide, a silica, a iron oxide and / or alumina, these particles possibly being untreated, or else treated by surface grafting with lipophobic groups. Thus, the particles (ii) can advantageously be particles of titanium oxide, preferably grafted by fluorinated groups, the particles of titanium oxide grafted by fluorinated groups being preferably obtained by grafting with compounds such as perfluoroalkylsilanes, by linear or cyclic polyorganosiioxanes containing perfluoroalkyl groups, by perfluoropolyethers, the particles based on titanium oxide treated with perfluoroalkylphosphates being particularly preferred. When phase (B) is of oily nature, the particles (ii) can alternatively be particles (of mineral or organic nature) on the surface of which water is deposited.

More generally, when phase (B) is oily in nature, it is generally preferable that the particles (ii) have a size less than 5 microns, preferably less than or equal to 1 micron, this size generally remaining between 20 and 100 nm.

According to a particular variant, when phase (A) is an oily phase, this phase can be immobilized on (or encapsulated in) a solid support, this solid support being dispersed in the powder (B) or else constituting the powder (B). Step (E) of the process of the invention consists in this particular case of releasing phase (A) by subjecting the powder (B) integrating phase (A) in an encapsulated or immobilized form to mechanical stress, this stress mechanical which can in particular be carried out by application of the powder (B) integrating the phase (A) on the surface of the skin. In this case, the powder (B) integrating phase (A) can be considered as a precursor of the composition having the consistency of a cream which will be obtained in fine. In this case, the oily phase can in particular be encapsulated within microcapsules, or even be adsorbed or deposited on the surface of the particles present in the solid powder (B). In this case, it is generally preferable for the particles (ii) to be mineral particles grafted on the surface with lipophobic groups, and, advantageously, these are the particles formed wholly or partly by a titanium oxide, a silica, an iron oxide and / or alumina treated with fluorinated groups as defined above.

According to another aspect, the present invention also relates to the various solid compositions which can be used according to a method of the present invention.

Thus, according to a particular aspect, the present invention relates to solid compositions which, when mixed with a liquid phase, lead extremely rapidly, and preferably instantaneously, to the formation of a composition having the texture of 'a cream.

In this context, according to a particular aspect, the present invention relates to a composition (C1) allowing the preparation (preferably instantaneously) of a cosmetic composition in contact with a liquid phase (A), said composition being made up in whole or in part with a solid powder, comprising:

(i) a gelling agent of said liquid phase (A); and

(ii) particles having surface properties giving them weak activity with respect to said liquid phase (A).

Preferably, in composition (C1), the gelling agent (i) and the metal oxide particles (ii) are chosen from the gelling agents and the preferred metal oxide particles defined above, depending on the nature of the liquid phase (A) envisaged.

Thus, the invention relates in particular to compositions suitable for the preparation of cosmetic compositions in contact with an aqueous phase at the time of the use of these compositions, in which the gelling agent (i) and the particles (ii) are as defined above in the specific case where phase (A) is aqueous in nature. In this context, the composition (C1) is advantageously a composition in which the gelling agent (i) is a starch, preferably crosslinked, and modified by carboxymethyl groups, this starch being particularly advantageously a modified starch such as "Covagel" sold by the company LCW (sodium carboxymethyl starch), the particles (ii) preferably being particles on the surface of which is deposited a hydrophobic compound such as an oil for example.

According to another aspect, the present invention also relates to compositions suitable for the preparation of cosmetic compositions in contact with an oily phase at the time of the application of said compositions, in which the gelling agent (i) and the particles (ii) are as defined above in the case where phase (A) is oily in nature. In this context, it is preferred that the gelling agent (i) be a modified mica (advantageously a fluorinated mica, preferably modified with potassium, such as aluminum fluoromagnesium potassium silicate sold by LCW under the name of "Submica M" ).

The composition (C1) in powder form, may or may not include a cosmetic active principle.

Specifically, the present invention relates to a kit for the preparation of cosmetic compositions, at the time of application of said compositions, comprising (I) a container comprising a composition (C1) as defined above, and (II) a container comprising the liquid phase (A), where the composition of the container (I) and / or the liquid phase of the container (II) contains a cosmetic active principle.

Typically, a composition (C1) according to the invention, in particular suitable for use in a kit of the aforementioned type, can have the following formula (the percentages given are percentages by mass expressed relative to the total mass of the composition ): - gelling agent (s) 0.1-90%

- particles, surface treated or not 0.1-60%

- oil, polar or non-polar 0-30%

- oil emulsifier (modified mica, for example) 0-10%

- Hydrophilic active (powder or liquid) 0-30%

- Lipophilic active ingredient 0-10%

According to another aspect, the present invention also relates to cosmetic compositions (C2) having the form of a powder and transforming into a cream during their application, these cosmetic compositions being constituted in whole or in part by a solid powder which comprises a phase liquid (A) in encapsulated or immobilized form on the surface of a solid, associated with:

(i) a gelling agent of said liquid phase (A); and

(ii) metal oxide particles having surface properties giving them a low affinity for the liquid phase (A).

The composition (C2) according to the invention is a composition of an extremely specific nature, which has the property of being in the form of a non-wetting solid during its transport and storage, and which is transformed into a composition having the texture and pleasant feel of a cream when it is applied.

Generally, in the composition (C2), the constituents (i) and (ii) are naturally to be adapted as a function of the nature of the liquid phase (A). Preferably, in composition (C2), the gelling agent (i) and the metal oxide particles (ii) are chosen from the gelling agents and the preferred metal oxide particles defined above, depending on the nature of the liquid phase (A) envisaged.

When the liquid phase (A) is of an aqueous nature, it is preferred that this aqueous phase (A) be immobilized at least in part on the surface of mineral particles grafted by hydrophobic groups, these particles preferably being particles based on mineral oxide (preferably based on titanium oxide), grafted by silane groups, preferably by -OSiR groups, where R denotes an alkyl group bearing from 5 to 18 carbon atoms, and. preferably between 7 and 10 carbon atoms (typically 8 carbon atoms), or share fluorinated groups such as perfluoroalkylphosphates.

Furthermore, when phase (A) is of an aqueous nature, it is preferred that the gelling agent (i) is a starch, preferably crosslinked, and modified with carboxymethyl groups, this starch preferably being a starch such as " Covagel "sold by the company LCW. The particles (ii) are most preferably in this case particles based on titanium oxide grafted by silane groups (preferably by -OSiR groups, where R denotes an alkyl group bearing from 5 to 18 carbon atoms, preferably between 7 and 10 carbon atoms, and typically 8 carbon atoms) as defined above, the aqueous phase then generally being adsorbed at least partially on the surface of these particles. Without wishing to be linked in any way to a particular theory, it seems possible to be advanced in this context that, in particular in the case of a composition (C2) where phase (A) is aqueous, where the gelling agent (i) is a modified starch, and where the particles (ii) are particles based on grafted titanium oxide, the water seems to be both immobilized on the surface of the particles (i) and within the gelling agent.

According to another variant, the composition (C2) may comprise a liquid phase (A) of oily nature, said oily phase (A) then being generally at least partially immobilized on the surface of mineral particles (ii) grafted on the surface with groups lipophobes, these particles being advantageously constituted in whole or in part by a titanium oxide, a silica, an iron oxide and / or alumina, preferably treated by grafting with compounds such as perfluoroalkylsilanes, polyhexafluoro (oxide of propylene), by linear or cyclic polyorganosiioxanes containing perfluoroalkyl groups, by perfluoropolyethers, the particles based on titanium oxide treated with perfluoroalkylphosphates being particularly preferred. According to this variant, it is most often advantageous for the gelling agent (i) to consist entirely or partially of particles of modified mica, preferably particles of fluorinated mica (in particular of the type of particles marketed under the name of "Submica M "by the company LCW).

Whatever its exact formulation, and whatever the nature of the immobilized phase (A), a composition of type (C2) as defined above is generally obtained by adding (most often all at once and in a manner fast) the liquid phase (A) to a solid mixture comprising the gelling agent (i) and the particles (ii), as a rule with relatively moderate stirring (typically between 1000 and 2000 revolutions per minute).

According to a particular aspect, the present invention also relates to cosmetic compositions in the form of powders resulting from the mixture of two or more compositions of type (C2) as defined above. According to this variant, it is possible, for example, to envisage compositions resulting from at least one composition of type (C2) where phase (A) is of aqueous nature and from at least one composition of type (C2) where phase (A ) is oily in nature.

Typically, a composition (C2) according to the invention can have the following formula (the percentages given are percentages by mass expressed relative to the total mass of the composition):

Solid phase:

- gelling agent (s) 0.1-15% - particles, surface treated or not 0.1-30%

- Hydrophilic or lipophilic active 0-30%

Liquid phase immobilized within the solid phase:

- water or oil, polar or non-polar 10-90%

- oil emulsifier (modified mica, for example) 0-10% - Hydrophilic or lipophilic active ingredient 0-30% As previously pointed out, the methods of the present invention as well as the compositions (C1) and (C2) implementing them can advantageously comprise, as gelling agent for aqueous phase, a modified starch such as " Covagel ".

With regard to these starches, the inventors have demonstrated that, surprisingly, while these modified starches are generally known to be unsuitable in cosmetics since they do not lead to gelation properties which are durable over time, the crosslinked and carboxymethyl starches such as "Covagel" can be advantageously used in cosmetics as gelling agents, in the context of the preparation of nomadic cosmetic compositions and in the context of particular cosmetic compositions (C2) in the form of a powder and transforming into a cream at the time of application. In fact, the inventors have demonstrated modified starches, and in particular crosslinked and carboxymethyl starches such as "Covagel", lead, by adding water, to the instant production of a composition having the soft texture and pleasant of a cream, and that these starches therefore make it possible to obtain extremely quickly cosmetic compositions based on water having particularly advantageous qualities of touch.

This specific use of modified starches such as "Covagel" type starches for the preparation of water-based cosmetic compositions at the time of their application, constitutes another specific object of the present invention.

Likewise, the inventors have demonstrated that the particles of modified micas, in particular the particles of fluorinated micas, and in particular the particles of fluorinated micas and modified with potassium, such as the particles marketed under the name " Submica M "by the company LCW, lead, by adding an oily phase, to the instantaneous production of a composition having the pleasant texture of a cream. and that these mica particles are therefore particularly suitable for instant manufacturing to obtain oil-based cosmetic compositions extremely quickly, to have a particularly pleasant feel.

According to another particular object, the invention also relates to this particular use of modified (and in particular fluorinated) mica particles such as "Submica M", for the extemporaneous preparation of cosmetic compositions based on a phase of nature oily when applied.

Various characteristics and advantages of the present invention will appear even more clearly in the light of the illustrative examples given below.

EXAMPLE 1 Composition in powder form instantly transforming into a composition having a cream texture by addition of water (day cream)

A composition (C1) according to the invention was prepared by mixing the following compounds (the percentages given are percentages by mass expressed relative to the total mass of the composition):

- Covagel * (sodium carboxymethyl starch - M = 30.10 ⁶ g / ^m ° l ^e ) ^: 30%

- Submica M * (aluminum silicate, fluoromagnesium and potassium) 5%

- Covabead LH 85 * (crosslinked polymethylmetacrylate) 30.5% - AC-5 sericite FSE * (aluminum and potassium silicate, cellulose) 10%

- Fucosorb * (seaweed extract) 10% ^<•

- LRI * solubilizer (PPG-26 buteth-26, PEG-40, hydrogenated castor oil) 2.5%

- Macarose ^* (Macadamia Temifolia, Rosa canina) 10% - Vital lipofactor * (Rosa canina, tocopherol acetate, retinyl palmitate, liquid paraffin, ascorbyl palmitate) 2.0%.

*; marketed by LCW

This composition can be used as a “nomadic” type cosmetic composition. Just before use, simply moisturize the formulation by adding water, and gently agitate the powder / water mixture, thereby obtains a structure with a creamy texture and appearance, of particularly pleasant touch.

EXAMPLE 2 Solid powder instantly transforming into a cream during application (slimming composition containing an immobilized aqueous phase)

The compounds used in this example and their proportions are reported below. The percentages given are percentages by mass expressed relative to the total mass of the final composition.

Solid powder:

- Covagel ^* (sodium carboxymethyl starch - M = 30.10 ⁶ g / ^m ° l ^e ) ^: 3.8%

- Serica 5 covasil 4.05 * (mica + silicone) 2.4%

- Talc covasil 4.05 * (talc + silicone) 3.3%

- PF-5 talc JA 46R * (talc treated with perfluoroalkylphosphates) 3.8% - Covabead LH 85 * (crosslinked methylmetacrylate beads) 2.4%

- PW covasil S1 * (titanium oxide treated with trimethoxycaprylylsilanes) 3.3%

Aqueous liquid phase:

- Water 65.7% - Lipofirm LCW * (slimming active ingredients) 7.5%

- Fucosorb * (algae extract) 1.9%

- PEG 400 5.6%

- preservatives 0.3%

*; marketed by LCW

The liquid phase was added all at once to the solid powder and the mixture was stirred at 1500 rpm for 10 minutes. We first obtain a gel structure, friable, which breaks gradually to gradually transform into a composition having the structure of a powder.

The powder obtained can be kept in this state and transported and, when applied to the skin, it takes on a creamy texture of pleasant feel.

EXAMPLE 3; Solid powder instantly transforming into cream during application (composition containing an immobilized oily phase)

A mixture of 15 g of PW Covafluor (titanium oxide grafted with fluorinated groups, sold by the company LCW), 5 g of talc JA R46 PF (talc treated with fluorinated groups, sold by the company LCW) was produced, 5 g of Submica M, 2 g of Covabead LH 170 (polymethacrylate beads, marketed by LCW). 30 g of Squatol S (hydrogenated polyisobutene, sold by LCW) were added to this mixture at one time.

The oily hydrogenated polyisobutene is integrated into the powder during stirring (1500 revolutions per minute for 10 minutes) and in the end a solid powder is transportable and storable in dry form and which takes the texture of a cream at the time. where it is applied to the skin.

Claims

1. A method of preparing a cosmetic composition having the texture of a cream, implemented by a user at the time of application of said cosmetic composition, said method comprising a step (E) consisting in bringing into contact:

(A) a liquid phase;

(B) a solid powder comprising:

(i) a gelling agent for the liquid phase (A); (ii) particles of mineral or organic nature having surface properties giving them a low affinity for the liquid phase (A); and

(C) a cosmetic active ingredient.

2. Method according to claim 1, characterized in that step (E) consists in adding the phase (A) to the solid powder (B) or in mixing the phase (A) and the powder (B).

3. Method according to claim 1, characterized in that the phase (A) is immobilized on a solid support or encapsulated within this solid support, said solid support constituting all or part of the powder (B), and in what step (E) consists in releasing phase (A) by subjecting the powder (B) which integrates phase (A) in immobilized form to mechanical stress, for example by applying powder (B) integrating the phase (A) on the surface of the skin.

4. Method according to claim 1, characterized in that phase (A) is an aqueous phase.

5. Method according to claim 4, characterized in that the gelling agent (i) is a starch modified with carboxymethyl groups.

6. Method according to claim 4 or according to claim 5, characterized in that the particles (ii) are particles on the surface of which an oily phase is deposited, or particles of hydrophobic polymers, or mineral particles grafted on the surface by hydrophobic groups, preferably among the silane, methicone, dimethicone, fatty acids, amino acids, lecithin, collagen, polyethylene, teflon, lauroyl lysine, polyfluorophosphate ethers groups, and mixtures of one or more of these groups.

7. Method according to claim 1, characterized in that phase (A) is an oily phase

8. Method according to claim 7, characterized in that the gelling agent (i) is chosen from micas, silicas, or clays.

9. Method according to claim 8 or according to claim 9, characterized in that the particles (ii) are mineral particles, untreated, or else treated by surface grafting with lipophobic groups, or particles on the surface of which is deposited water.

10. Kit for the preparation of a cosmetic composition at the time of its application, comprising:

(I) a container, comprising a composition (C1) wholly or partly constituted by a solid powder, comprising:

(i) a gelling agent of said liquid phase (A); and

(ii) particles of mineral or organic nature having surface properties giving them a low affinity with respect to said liquid phase (A); and

(II) a container, comprising said liquid phase (A), where the composition (C1) or the liquid phase (A) contains a cosmetic active.

11. Kit according to claim 10, in which the gelling agent (i) is a starch modified by carboxymethyl groups, and in which phase (A) is an aqueous phase.

12. Kit according to claim 10, in which the gelling agent (i) is a modified, preferably fluorinated mica, and in which phase (A) is an oily phase.

13. Cosmetic composition (C2), in the form of a powder transforming into a cream during its application, constituted in whole or in part by a solid powder which comprises a liquid phase (A), in encapsulated form or immobilized on the surface of a solid, associated with:

(i) a gelling agent of said liquid phase (A); and

(ii) particles of mineral or organic nature having surface properties giving them a low affinity with respect to said liquid phase (A).

14. Composition according to claim 13, in which the liquid phase

(A) is of an aqueous nature, in which the gelling agent (i) is a starch modified by carboxymethyl groups and where the particles (ii) are particles based on titanium oxide grafted by silane groups or share fluorinated groups.

15. The composition of claim 13, wherein the liquid phase

(A) is of an oily nature, in which the gelling agent (i) consists in whole or in part of modified mica particles, and in which the particles (ii) are metal oxide particles grafted on the surface by lipophobic groups .

16. Use of a starch modified with carboxymethyl groups, as a gelling agent for the instant preparation of a water-based cosmetic composition at the time of its application.

17. Use of fluorinated mica particles as a gelling agent for the instant preparation of a cosmetic composition based on an oily phase at the time of its application.

18. Use according to claim 17, in which the mica particles are fluorinated potassium modified mica particles.